The present invention generally relates to an apparatus and method for analysis of engines. More particularly, the present invention relates to an apparatus and method to pickup secondary ignition voltage.
Conventional combustion, reciprocating engines are widely used as automotive engines. A conventional engine (e.g., single-cycle, two-cycle and others) is typically composed of an engine or cylinder block assembly having one or more cylinders therein. A piston is slidably disposed in the cylinder and moves reciprocally within the cylinder. A cylinder head at one end of the cylinder completes the cylinder assembly. The cylinder head typically contains the valves (intake and exhaust) and the spark plug. The spark plug typically ignites a pre-mixed fuel that is injected by the intake valve into a combustion chamber and helps to define an ignition event.
Should an ignition event not occur or the cylinder misfires, it can reduce the power output of the engine, can cause low fuel economy and poor performance. Engine analyzers are used to analyze the performance of internal combustion engines by analyzing ignition events of their cylinders.
A conventional digital analyzer can convert analog signals to digital signals for display on an oscilloscope, which displays snapshots of discrete portions of the signals as waveforms. In the case of multiple cylinders, waveforms showing the primary and the secondary ignition voltages are displayed. The voltages are acquired from a primary lead and a secondary lead (referred to as pickups) that are connected to an ignition coil at one end. The primary and secondary leads are connected at the other end to the analyzer, which runs tests and obtains data that is converted and displayed as waveforms. The secondary leads can be a capacitive pickup and the high voltage signals are capacitively sensed and converted to waveforms by the analyzer.
In newer engines, there can be one ignition coil per cylinder, referred to as xe2x80x9ccoil-on-plugxe2x80x9d, where each coil is typically mounted on top of the spark plug. The primary voltage is measured with a direct connection via a primary lead connected to the ignition coil. Conventionally, the secondary lead clamps on a spark plug wire, however, this is not possible on newer engines with xe2x80x9ccoil-on-plugxe2x80x9d because the coil covers the plug. Additionally, conventional secondary capacitive pickups also have circuitry built thereon to boost the secondary voltage signals. The circuits, if not working properly, can relay faulty voltage readings to the analyzer. The circuits also add additionally costs and production time to the secondary capacitive pickups. Without information regarding secondary voltage from the secondary leads, any calibration or analysis of the engine will be incorrect and incomplete. Thus it is important to obtain secondary voltage in order to proper analyze the engine and the ignition events of each cylinder.
Therefore, there is a need for a low cost apparatus and method to obtain secondary voltage in engines so that the analyzer can analyze and display accurate data, particularly one that can be used with coil-on-plug arrangements, if desired.
Embodiments of the present invention generally provide for an apparatus and method to allow the analyzer to collect secondary voltage of an ignition event. In one embodiment, a pickup apparatus for use with a lead of an analyzer that analyzes an engine having an ignition coil, the apparatus can include a first body member capable of receiving voltage signals from the ignition coil, a first attachment portion that can extend from the first body member and can attach the first body member to the ignition coil, and a first spade integral with the pickup apparatus that can extend from one of the first body member and the first attachment portion and can be connectable to the lead, wherein the first body member, the first attachment portion, and the first spade can be in communication with each other and can relay voltage signals from the ignition coil to the lead. The first body member, the first attachment portion, and the first spade can be a unitary structure and can be made from a conductive material. The conductive material may be selected from 304 stainless steel, copper, aluminum, brass, ferrous metal, and a combination thereof. The pickup apparatus can further include a second body member capable of receiving voltage signals from the ignition coil, a second attachment portion that can extend from the second body member and can attach the second body member to the ignition coil, a second spade integral with the pickup apparatus that can extend from one of the second body member and the second attachment portion and can be connectable to the lead, and a connector connecting the first and second body members, wherein the first and second body members, the first and second attachment portions, the first and second spades can be in communication with each other and can relay voltage signals from the ignition coil to the lead. The second body member and the second attachment portion can have a shape complimentary to the ignition coil to fit on the ignition coil. The first and second body members, the first and second attachment portions, and the first and second spades can be made from a conductive material. The conductive material can be 304 stainless steel, copper, aluminum, brass, ferrous metal and a combination thereof. Additionally, the first body member and the first attachment portion can have a shape complimentary to the ignition coil to fit on the ignition coil. The first and second spades can be of same thickness as the rest of the pickup apparatus and can be continuous throughout.
In another embodiment, a method of conveying signals from an ignition coil to an engine analyzer that can include attaching a secondary pickup to the ignition coil to receive signals from the ignition coil, receiving the signals from the ignition coil with the secondary pickup, and relaying the received signals to the engine analyzer. The signals may be secondary voltage signals, and the receiving step may include capacitively receiving the secondary voltage signals with the secondary pickup. The step of relaying the signals can further include the step of connecting a lead to the pickup.
In an alternative embodiment, a pickup apparatus for use with a lead of an analyzer that analyzes an engine having an ignition coil can include a first means for receiving voltage signals from the ignition coil, a first means for attaching that can extend from the means for receiving and can attach the means for receiving to the ignition coil, and a first means for connecting that can extend from one of the first means for receiving and the first means for attaching and can be connectable to the lead, wherein the first means for receiving, the first means for attaching, and the first means for connecting are in communication with each other and can relay voltage signals from the ignition coil to the lead. The first means for receiving, the first means for attaching, and the first means for connecting can be a unitary structure and can be made from a conductive material. The conductive material can be selected from 304 stainless steel, copper, aluminum, brass, ferrous metal, and a combination thereof. The pickup apparatus can further include a second means for receiving voltage signals from the ignition coil, a second means for attaching that can extend from the second means for receiving and can attach the second means for receiving to the ignition coil, a second means for connecting that can extend from one of the second means for receiving and the second means for attaching and can be connectable to the lead, and a coupling means for coupling the first and second means for receiving together, wherein the first and second means for receiving, the first and second means for attaching, and the first and second means for connecting can be in communication with each other and can relay voltage signals from the ignition coil to the lead. The second means for receiving, the second means for attaching, and the second means for connecting can be made from a conductive material that can be selected from 304 stainless steel, copper, aluminum, brass, ferrous metal, and a combination thereof.
There has thus been outlined, rather broadly, the more important features of the invention in order that the detailed description thereof that follows may be better understood, and in order that the present contribution to the art may be better appreciated. There are, of course, additional features of the invention that will be described below and which will form the subject matter of the claims appended hereto.
In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein, as well as the abstract, are for the purpose of description and should not be regarded as limiting.
As such, those skilled in the art will appreciate that the conception upon which this disclosure is based may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention.